Taking Temperature Processing Out of Dye‐Sensitized Solar Cell Fabrication: Fully Laser‐Manufactured Devices

Abstract

a light-absorbing dye, an electrolyte and a platinized conductive top substrate.Different from more established photovoltaic technologies, standard, industrial, reliable, highly automated, and effi cient fabrication procedures have yet to be fully defi ned and integrated for DSCs. Most fabrication steps currently entail the use of printing processes (such as screen printing of the nc-TiO 2 and Pt precursor layers) and of high temperature treatments in ovens to fi re the nc-TiO 2 and Pt precursor fi lms at 400-550 °C. Alternative low-tempteature approaches suitable for plastic substrates have been intensively studied and reported in the literature. [8][9][10][11][12] The nc-TiO 2 fi lm sensitization is usually achieved by soaking the fi lms in a dye solution, and devices are sealed by means of a thermoplastic gasket (heated and pressed at around 100 °C) followed by electrolyte injection.Lasers have recently started to be utilized in DSCs processing. [13][14][15][16][17][18] In particular, we have reported an effi cient, effective, scalable, and low embodied energy sintering procedure for the nc-TiO 2 fi lm. [19][20][21] Here we demonstrate that all the primary DSC manufacturing steps that required temperature treatments and in particular, sintering of the TiO 2 fi lm, curing of the Pt precursor, and device sealing, can be successfully and effi ciently carried out via laser assisted processes controlled by means of raster scanning systems (RSLSs). We believe this to be the fi rst demonstration of a device which is also effi cient and durable, where absolutely no temperature treatments were applied (all replaced by laser processing) together with a method for the defi nition of the cell pattern. The new processes were introduced while maintaining an uncompromising level of performance (6% conversion effi ciency) and durability (lifetime), the same as devices manufactured by conventional processes.We developed laser fabrication processes for the 1) patterning of the active layer, 2) sintering of the TiO 2 layer, 3) curing of the Pt precursor catalyst, and 4) encapsulation via a perimeter thermoplastic gasket. We present each of these developments here. Results and Discussion Laser-Patterning and Laser-Sintering of nc-TiO 2 FilmsAn important feature of DSC technology consists in the use of printing/masking procedures to defi ne the main active Pt and

Flexible Perovskite Photovoltaic Modules and Solar Cells Based on Atomic Layer Deposited Compact Layers and UV‐Irradiated TiO2 Scaffolds on Plastic Substrates

“…Energy Mater. [ 40,41 ] Spin coating was used for the perovskite and HTM layers since we found these to be transferable over the module size. For the remaining mesoporous TiO 2 , perovskite and HTM layers, a careful manual removal was performed using a tip dipped in a DMF/chlorobenzene solution.…”

Laser-Patterning Engineering for Perovskite Solar Modules With 95% Aperture Ratio

“…In order to eliminate the peculiar limitations of the near-IR P2 laser patterning, we performed the P2 with a UV laser considering that the absorbance of TiO2 at λ = 355 nm is ~2.5 times of the one of FTO, while for λ = 1064 nm TiO2 and FTO have a similar absorption. [50] A 10 ps, Nd:YVO4, raster scanning laser, with a λ = 355 nm (Time-Bandwidth Duetto) was used for the P2 process to remove the EPH. The application of a ultra-short pulse laser permits the ablation of materials maintaining a very low heat diffusion through the target, since the time needed for the heat transfer from energized electrons to the lattice ions is in the order of nanoseconds [51] and an adequate picoseconds laser pulse power can evaporate irradiated material before heat transfer takes place.…”

Laser Processing in the Manufacture of Dye‐Sensitized and Perovskite Solar Cell Technologies

“…Patterning of the nc‐TiO 2 films is also possible with lasers for the fabrication of DSSCs, as reported in Ref. . A nc‐TiO 2 film was firstly deposited over a TCO/glass substrate, which was successively removed by using a pulsed (400 kHz rep. rate), picosecond (pulse duration 7 ps), frequency‐doubled ytterbium YAG disk laser (emission wavelength λ =515 nm maximum average power 30 W) with a fixed scan speed (8 m s −1 ), and optimized by varying the laser fluence.…”

“…In the DSSC field, there has even been a recent demonstration milestone that all temperature processing through conventional means (e.g. ovens, hotplates) can be taken out of the manufacturing and processing, and be completely replaced with the utilization of a number of different lasers . Furthermore, even though PSCs have only recently exploded onto the scene, the application of lasers has already been surprisingly creative.…”